Description

These functions operate on wide-character strings terminated by wchar_tNULL characters. During
appending or copying, these routines do not check for an overflow condition
of the receiving string. In the following, ws, ws1, and ws2 point
to wide-character strings terminated by a wchar_t NULL.

wcscasecmp(), wcsncasecmp()

The wcscasecmp() function is the wide-character equivalent of the strcasecmp(3C) function. It
compares the wide-character string pointed to by ws1 to the wide-character string
pointed to by ws2, ignoring case differences. It returns 0 if the
wide-character strings at ws1 is equal to ws2 except for case differences.
It returns a positive integer if ws1 is greater than ws2 and
a negative integer if ws1 is smaller than ws2, ignoring case.

The wcsncasecmp() function is the wide-character equivalent of the strncasecmp(3C) function. It
compares at most n wide-characters from the wide-character string pointed to by ws1
to the wide-character string pointed to by ws2, while ignoring differences in
case. It returns 0 if the wide-character strings at ws1 and ws2,
truncated to at most length n, are equal except for case distinctions. It
returns a positive integer if truncated ws1 is greater than ws2 and
a negative integer if truncated ws1 is smaller than ws2, ignoring case.

wcscat(), wscat()

The wcscat() and wscat() functions append a copy of the wide-character string
pointed to by ws2 (including the terminating null wide-character code) to the
end of the wide-character string pointed to by ws1. The initial wide-character code
of ws2 overwrites the null wide-character code at the end of ws1.
If copying takes place between objects that overlap, the behavior is undefined.
Both functions return s1; no return value is reserved to indicate an error.

wcsncat(), wsncat()

The wcsncat() and wsncat() functions append not more than n wide-character codes
(a null wide-character code and wide-character codes that follow it are not
appended) from the array pointed to by ws2 to the end of the
wide-character string pointed to by ws1. The initial wide-character code of ws2
overwrites the null wide-character code at the end of ws1. A terminating
null wide-character code is always appended to the result. Both functions return ws1;
no return value is reserved to indicate an error.

wcscmp(), wscmp()

The wcscmp() and wscmp() functions compare the wide-character string pointed to by
ws1 to the wide-character string pointed to by ws2. The sign of
a non-zero return value is determined by the sign of the difference between
the values of the first pair of wide-character codes that differ in
the objects being compared. Upon completion, both functions return an integer greater
than, equal to, or less than zero, if the wide-character string pointed
to by ws1 is greater than, equal to, or less than the wide-character
string pointed to by ws2.

wcsncmp(), wsncmp()

The wcsncmp() and wsncmp() functions compare not more than n wide-character codes
(wide-character codes that follow a null wide character code are not compared)
from the array pointed to by ws1 to the array pointed to by
ws2. The sign of a non-zero return value is determined by the
sign of the difference between the values of the first pair of
wide-character codes that differ in the objects being compared. Upon successful completion,
both functions return an integer greater than, equal to, or less than zero,
if the possibly null-terminated array pointed to by ws1 is greater than,
equal to, or less than the possibly null-terminated array pointed to by
ws2.

wcscpy(), wscpy(), wcpcpy()

The wcscpy(), wscpy(), and wcpcpy() functions copy the wide-character string pointed to
by ws2 (including the terminating null wide-character code) into the array pointed
to by ws1. If copying takes place between objects that overlap, the behavior
is undefined.

The wcscpy() and wscpy() functions return ws1. The wcpcpy() function returns a
pointer to the terminating null wide-character code copied into ws1.

wcsncpy(), wsncpy(), wcpncpy()

The wcsncpy(), wsncpy(), and wcpncpy() functions copy not more than n wide-character
codes (wide-character codes that follow a null wide character code are not
copied) from the array pointed to by ws2 to the array pointed to
by ws1. If copying takes place between objects that overlap, the behavior
is undefined.

If the array pointed to by ws2 is a wide-character string that
is shorter than n wide-character codes, null wide-character codes are appended to
the copy in the array pointed to by ws1, until a total
n wide-character codes are written. The wcsncpy() and wsncpy() functions return ws1. The
wcpncpy() function returns a pointer to the last wide character written.

wcsdup()

The wcsdup() function is the wide-character equivalent of the strdup(3C) function. It
returns a pointer to a new wide-character string whose initial contents is a
duplicate of the wide-character string pointed to by s. Memory for the
new wide-character string is allocated with malloc(3C) and can be freed with a
call to free(3C). A null pointer is returned and errno set to
ENOMEM if there is insufficient memory available for the duplicate string.

wcslen(), wslen(), wcsnlen()

The wcslen() and wslen() functions compute the number of wide-character codes in
the wide-character string to which ws points, not including the terminating null
wide-character code. Both functions return ws; no return value is reserved to indicate
an error.

The wcsnlen() is the wide-character equivalent of the strnlen(3C) function. It returns
the number of wide-characters in the string pointed to by ws, not
including the terminating null wide-character code but at most maxlen, while never
looking beyond the first maxlen characters. It returns maxlen if there is
no terminating null wide-character code among the first maxlen wide characters pointed to
by ws.

wcschr(), wschr()

The wcschr() and wschr() functions locate the first occurrence of wc in
the wide-character string pointed to by ws. The value of wc must
be a character representable as a type wchar_t and must be a
wide-character code corresponding to a valid character in the current locale. The
terminating null wide-character code is considered to be part of the wide-character
string. Upon completion, both functions return a pointer to the wide-character code,
or a null pointer if the wide-character code is not found.

wcsrchr(), wsrchr()

The wcsrchr() and wsrchr() functions locate the last occurrence of wc in
the wide-character string pointed to by ws. The value of wc must
be a character representable as a type wchar_t and must be a
wide-character code corresponding to a valid character in the current locale. The
terminating null wide-character code is considered to be part of the wide-character
string. Upon successful completion, both functions return a pointer to the wide-character
code, or a null pointer if wc does not occur in the wide-character
string.

windex(), wrindex()

The windex() and wrindex() functions behave the same as wschr() and wsrchr(),
respectively.

wcspbrk(), wspbrk()

The wcspbrk() and wspbrk() functions locate the first occurrence in the wide
character string pointed to by ws1 of any wide-character code from the
wide-character string pointed to by ws2. Upon successful completion, the function returns a
pointer to the wide-character code, or a null pointer if no wide-character
code from ws2 occurs in ws1.

wcswcs()

The wcswcs() function locates the first occurrence in the wide-character string pointed
to by ws1 of the sequence of wide-character codes (excluding the terminating
null wide-character code) in the wide-character string pointed to by ws2. Upon successful
completion, the function returns a pointer to the located wide-character string, or
a null pointer if the wide-character string is not found. If ws2
points to a wide-character string with zero length, the function returns ws1.

wcsspn(), wsspn()

The wcsspn() and wsspn() functions compute the length of the maximum initial
segment of the wide-character string pointed to by ws1 which consists entirely
of wide-character codes from the wide-character string pointed to by ws2. Both
functions return the length ws1; no return value is reserved to indicate
an error.

wcscspn(), wscspn()

The wcscspn() and wscspn() functions compute the length of the maximum initial
segment of the wide-character string pointed to by ws1 which consists entirely
of wide-character codes not from the wide-character string pointed to by ws2. Both
functions return the length of the initial substring of ws1; no return
value is reserved to indicate an error.

wcstok(), wstok()

A sequence of calls to the wcstok() and wstok() functions break the
wide-character string pointed to by ws1 into a sequence of tokens, each
of which is delimited by a wide-character code from the wide-character string
pointed to by ws2.

Default and other standards

The third argument points to a caller-provided wchar_t pointer into which the
wcstok() function stores information necessary for it to continue scanning the same
wide-character string. This argument is not available with the XPG4 and SUS
versions of wcstok(), nor is it available with the wstok() function.
See standards(5).

The first call in the sequence has ws1 as its first argument,
and is followed by calls with a null pointer as their first
argument. The separator string pointed to by ws2 may be different from
call to call.

The first call in the sequence searches the wide-character string pointed to
by ws1 for the first wide-character code that is not contained in
the current separator string pointed to by ws2. If no such wide-character
code is found, then there are no tokens in the wide-character string pointed
to by ws1, and wcstok() and wstok() return a null pointer. If
such a wide-character code is found, it is the start of the
first token.

The wcstok() and wstok() functions then search from that point for a
wide-character code that is contained in the current separator string. If no
such wide-character code is found, the current token extends to the end
of the wide-character string pointed to by ws1, and subsequent searches for a
token will return a null pointer. If such a wide-character code is
found, it is overwritten by a null wide character, which terminates the
current token. The wcstok() and wstok() functions save a pointer to the following
wide-character code, from which the next search for a token will start.

Each subsequent call, with a null pointer as the value of the
first argument, starts searching from the saved pointer and behaves as described
above.

Upon successful completion, both functions return a pointer to the first wide-character
code of a token. Otherwise, if there is no token, a null
pointer is returned.